Clearwater and Tampa want to turn flushed water into drinking water. Is it safe?

Twenty years ago some people called it "Twerp." Others, wrinkling their noses, called it "toilet-to-tap," or something more vulgar.

In 1998, Tampa tried to boost its drinking water supply by supplementing it with treated wastewater, calling the program the "Tampa Water Reuse Project," or TWRP. Scientists, health officials and environmental activists said it was too risky, warning about harmful chemicals, drugs and microbes getting through. In the end, it faded away.

Now the idea is back with a new identity. Clearwater is close to getting a state permit to use treated wastewater for what it calls "groundwater replenishment," while Tampa has a public hearing scheduled for July for what it calls its"Tampa Augmentation Project." Meanwhile Tampa Bay Water, the utility that provides wholesale water to three counties, has been studying doing something similar, called potable reuse, as part of its master water plan.

The questions about recycling treated wastewater as drinking water that were raised 20 years ago remain — but some of the answers are different. One of the scientists whose report helped kill TWRP in 1998 now says using treated wastewater that way is safe.

"Monitoring has changed, and the technology has changed," said Joan Rose, an expert on microbes who back then taught at the University of South Florida and now is co-director of the Center for Water Sciences at Michigan State University. "Definitely, the acceptance (by the public) has changed."

Yet, as the efforts at rebranding the product show, a stigma remains for recycling wastewater. One of the biggest criticisms remains, too. Neither the Florida Department of Environmental Protection nor the U.S. Environmental Protection Agency has established any rules for building and running a potable reuse project. According to a 2017 EPA report, no state has rules dictating how much filtering is sufficient, or requiring inspections of the operation.

The only rules governing the human use of recycled wastewater are the federal drinking water standards. But those standards do not cover some harmful things commonly found in wastewater, such as antibiotics and antidepressants. Twenty years ago, that was a potent argument against approving TWRP.

"We're unable to detect all the contaminants," the head of a National Research Council panel told Pinellas County commissioners in 1998. "Merely meeting the drinking water standards is not adequate."

The report from his panel — which included Rose — warned that potable reuse was "a solution of last resort, to be adopted only when all other alternatives … have been evaluated and rejected."

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This spring, when the Florida Legislature passed a bill that would encourage more utilities to build potable reuse plants, opponents cited those same concerns about the harmful things in wastewater, and Gov. Rick Scott vetoed the bill. Opponents contended potable reuse was just a risky ploy to boost development while avoiding tough choices on how much water Floridians waste.

"They'd rather stick their heads in a toilet than link growth to the resources that support growth," said Linda Young of the Panhandle-based Clean Water Network.

Those concerns continue to fuel opposition. St. Petersburg environmental lawyer Tom Reese, who battled the TWRP plan 20 years ago, says he once worked in a funeral home that routinely flushed the leftovers from the embalming process into the sewer.

"Do you want to drink water that has the liquid out of people's organs in it?" he asked.

However, Tampa's public works administrator, Brad Baird, said testing of the 50 to 60 million gallons of effluent produced every day by the Howard F. Curran Wastewater Plant has turned up only a minor amount of harmful chemicals. That effluent now goes into Tampa Bay, when it could be put to better use, he said.

In parts of Tampa and St. Petersburg treated wastewater is used to water lawns. But it's not treated sufficiently to drink.

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Back when Tampa tried to push its TWRP plan, there were hardly any other regions using treated wastewater for their water supply. Now it's used by utilities in California, Virginia, Texas, Georgia and Arizona, as well as Brazil, Australia, South Africa and Singapore.

Singapore's utility uses a three-stage process — including the use of ultraviolet radiation — to turn its effluent into a drinkable product it calls "NEWater," said George Madhavan of Singapore's water agency. Before producing a drop of the stuff, Singapore spent a year persuading the public it was safe.

That included press tours, expert testimony from scientists and even the creation of "a state-of-the-art water museum that would act as a one-stop center for anyone looking to understand how NEWater is produced and how it plays a part in Singapore's water strategy," Madhavan said. "Visitors could actually see the membranes used in the purification process" allowing them to view how it removes "bacteria, viruses, endocrine disrupters, antibiotics."

No similar effort has been undertaken in Florida, although Clearwater sent around a pair of vans with the "Groundwater Replenishment" slogan emblazoned on the sides.

In 2016, Clearwater became the first city in Florida to launch a $33 million project to inject treated wastewater into the ground, to supplement the supply of drinking water in the aquifer. Once begun, the city could start to pump up to 3 million gallons of treated water a day into the aquifer.

To get to this point, Clearwater spent seven years studying whether to do it. That included building a small-scale plant in 2013. For a year they tested the water it produced to see how clean it was, and it passed every test, thanks to what utilities director David Porter called "FAT — Full Advanced Treatment" of the wastewater.

Clearwater's plans copy the largest potable reuse plant in the world, the 100-million-gallon-a-day one that Orange County, Calif., opened in 2008. One key aspect of the Orange County plant's planning involved setting up an independent advisory panel of independent scientists and engineers — including Rose — to provide oversight, according to Mike Wehner of the Orange County Water District. No similar oversight board has been proposed for either the Tampa or Clearwater projects.

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For Clearwater officials, the one remaining issue is whether the cost has exceeded what the city wants to pay for it, said the city's utilities director, David Porter. The city is already anticipating a property tax hike to resolve a budget deficit, plus seeking $69 million in public money to renovate the Philadelphia Phillies' spring training baseball complex.

When the Tampa City Council voted in 2016 to pursue a similar project, which would involve running the treated effluent through the Tampa Bypass Canal, Baird hailed it as "a game-changer that can resolve drinking water supply problems for Tampa and the region for many decades to come."

The broader question is whether this is the best, most cost-effective way to meet Florida's future water needs. One water expert suggested that conserving water can be a cheaper and less risky way to provide for the state's future.

"Engineers can clean water and even make it sterile," said Cynthia Barnett, the author of three books on water and an environmental fellow in residence at the University of Florida's Graham Center. "But in terms of whether it's a good idea for Florida, it seems, like desalination, an expensive and high-energy prospect in a place that gets a ton of rain and hands out large groundwater permits so freely."

The largest users of water in Florida aren't homeowners, but farmers. Agricultural irrigation accounts for more than 60 percent of all freshwater consumed in Florida.

But according to Alison Adams, who recently retired after 20 years as Tampa Bay Water's top water supply expert, farmers aren't allowed to use recycled wastewater to irrigate their strawberries and tomatoes. No matter how thoroughly filtered it might be, no one wants treated effluent touching the fruits and vegetables that people will eat.